Joby completes initial FAA Systems, Compliance Reviews for eVTOL aircraft
Sandia team develops GaN diode that is significant step toward protecting grid from EMPs

Researchers find capillary-fed electrolysis cell can deliver hydrogen at 98% cell energy efficiency

In an open access paper published in Nature Communications, researchers from the University of Wollongong in Australia report that their capillary-fed electrolysis cell demonstrates water electrolysis performance exceeding commercial electrolysis cells, with a cell voltage at 0.5 A cm−2 and 85 °C of only 1.51 V, equating to 98% energy efficiency, with an energy consumption of 40.4 kWh/kg hydrogen (vs. ~47.5 kWh/kg in commercial electrolysis cells).

With this level of cell energy efficiency—well above International Renewable Energy Agency’s (IRENA) 2050 target and significantly better than existing electrolyzer technologies—hydrogen production cost could be well below US$1.50/kg.

This approach to water electrolysis supplies water to the hydrogen- and oxygen-evolving electordes via capillary-induced transport alone a porous inner-electrode separator. This leads to inherently bubble-free operation at the electrodes.


Inspired by the historic evolution of water electrolysis cell architectures culminating in the direct production of one of the gases, the Capillary-Fed Electrolysis cell directly produces both gases. Liquid electrolyte is continuously drawn up the separator by a capillary effect, from a reservoir at the bottom of the cell. The porous, hydrophilic separator sustains the flow rate required for water electrolysis. Hodges et al.

The technology, invented by scientists at the University of Wollongong, is now being commercialized by Hysata, with backing from IP Group and the Clean Energy Finance Corporation (CEFC).

Paul Barrett, CEO of Hysata, said the company is on a clear pathway to commercialise the world’s most efficient electrolyser and reach gigawatt scale hydrogen production capacity by 2025.

Gerry Swiegers, Chief Technology Officer at Hysata, says said the overall design of the Hysata electrolyser system is simpler than existing technologies.

Electrolyzers have been around for 200 years, however the large amounts of renewable electricity required to produce green hydrogen and the overall cost of electrolysers today has prevented large-scale uptake of green hydrogen.

Hysata’s overall electrolyser system has been designed for ease of manufacturing, scaling and installation, delivering 95 percent overall system efficiency, equivalent to 41.5 kWh/kg, compared to 75 percent or less for existing electrolyser technologies. For hydrogen producers, this will significantly reduce both the capital and operational costs to produce green hydrogen.

—Gerry Swiegers


  • Hodges, A., Hoang, A.L., Tsekouras, G. et al. (20220 “A high-performance capillary-fed electrolysis cell promises more cost-competitive renewable hydrogen.” Nat Commun 13, 1304 doi: 10.1038/s41467-022-28953-x



If this really works out, it will be a game changer.
You will still have to store and transport the H2, but at least you will be able to generate it without much losses.
Impressive - a real breakthrough if it scales.


That'll raise the overall "well to wheels" efficiency from 15 to 20%. That's still PP and absolutely nothing to brag about.


store and transport
Make hydrogen where you dispense it


Yes, SJC.  Let's have tens of thousands of Fukushima-scale hydrogen bombs all over our cities and towns, where the dispensers are.  I'm sure that will be popular with the public... NOT!

The one problem the capillary cell cannot solve is the capital cost problem with "renewable" power.  You need to size the cell for peak power generation, but you only get to use it at a fraction of its capacity.  You'd get much cheaper operation if you built out nuclear to serve peak load and ran electrolysis as a dump load.


@yoatmon: Source for your claim that the current well-to-wheel efficiency for FCEV is 15%? What is it for an EV for comparison?

@Engineer-Poet: Evidence to back that FCEVs are Fukushima-scale hydrogen bombs?

I find it interesting how eager people are to push disinformation when it comes to hydrogen.


The EP the looney babbles

Evidence to back that FCEVs are Fukushima-scale hydrogen bombs?

I didn't say "vehicles", I said "dispensers".  This analysis was done more than half a decade ago:


An analysis of the amount of hydrogen taking part in the explosions that happened during the Fukushima-Daiichi (Unit 1) nuclear power plant accident is presented herein. Through a series of analytic approximations and numerical calculations of increasing complexity, it has been possible to estimate that 130 kg of H2 was involved in the explosion. Also, the strength of the resulting explosion was examined determining that even with a significantly smaller amount of hydrogen taking part, a devastating explosion would have occurred regardless.

130 kg H2 is roughly enough to refuel 13-20 vehicles.  The inventory of any decent dispensing station would be at least that much.  That makes them possible (even likely, if failure is engineered) bombs.


Im ready to buy and im not alone. They talk about hydrogen on bloomberg youtube.


Its trivial to write knocking copy on any energy source with enough energy to push vehicles around, if pre-existing prejudice demands it.

The amount of energy in storage batteries is non-trivial, as is that in petrol stations.

The notion that there are some sort of unique and insuperable obstacles in using hydrogen, which we have been doing successfully in bulk not for decades but hundreds of years, is polemic not sound judgement.


@Engineer-Poet, come on, any combustible gas mixed with air and a spark will ignite, so what? Hydrogen is contained in hydrogen tank, no real danger. If there is a leak it will leak up in the air, if this is inside building it will be trapped in the ceeling. That is what happend in Fukushima.

Process of producing hydrogen with electrolysis was at 60-80% efficiency, so this 97% could be a game changer, with fuel cell (eg. Toyota) 60% efficiency, the round trip efficiency is above 50% + waste heat from fuel cell, can be used for home heating. This good seasonal solution, for three winter months, where there is little to no solar energy.


The point is that the vapor mix of gasoline+air in fuel tanks is NOT combustible; it's too fuel-heavy to burn, so not a hazard.  This is not true of hydrogen.

I think we'll need lots of hydrogen, but it's going to present all kinds of problems we aren't familiar with.


There have been 12 safety incidents after Fukushima involving H2 operations (
Today there are only 53 Hydrogen Fueling Station Locations (
The safety implications of managing tens of thousands of H2 dispensing locations would require extensive regulations, training, and capital investment.


@ pdd:
Currently, the efficiency of electrolysis amounts to 70%. The efficiency of a FC reaches 60%. 60% of 70% ='s 42 %. That is already a loss of 58%.
Compressing the H2 for storage at a centralized point of H2-production at approx. 800 bar is achieved with a further penalty at 12%. The remaining efficiency is now at 30%.
The distribution of H2 from central storage to filling stations is accomplished via special tank trucks. Pumping the H2 from the storage tank to the tank truck penalizes efficiency with further 5% losses. The truck itself is propelled with either fossil fuel or an electric drive causing further efficiency losses dependent on the distance traveled. Upon arrival at the filling station, the H2 is pumped from the truck to the storage tank at the filling station lowering the overall efficiency once again.
Finally, the H2 at the filling station is pumped into the tank of a car via electric energy up to 800 bar and further lowering of the overall efficiency.
With lots of luck and a huge portion of optimism you may be able to achieve the overall 15% efficiency which I mentioned in my previous post. The improvement of the electrolysis process as mentioned in the article amounts to an approx. 5% increase when considering the overall "well to wheels" efficiency which is really nothing to brag about.


@ pdd:
A BEV with an axial flux motor ( efficiency =/> 95%) with a Li-ion battery (newest SOA) easily achieves > 90% overall efficiency. Besides that, I wouldn't take an H2 vehicle as a gift, let alone buy one, because I wouldn't enjoy a ride atop an incendiary bomb. The corrective maintenance of those vehicles is ludicrously expensive because for safety reasons all piping in the car must be flushed with CO2 before initiating maintenance.

The comments to this entry are closed.